I was surprised to see testosterone mentioned as having a possible relationship with I.Q. I've actually read that high levels of the natural hormone progesterone (not to be confused with synthetic progestin), has been studied as a contributing factor in giftedness. I have no idea if it's true, but what an interesting concept!
As for lowering I.Q., I've read accusations that fluoride can do that. Again, I'm not a physician and have no way of knowing if the studies done are valid.
Here's
one article on the effect of progesterone on the fetus.
As a side note, many miscarriages are due to a low level of progesterone early in the pregnancy. Tests will diagnose this. Progesterone suppositories can be given by the OB/Gyn to correct the levels.
Maybe TMI, but I was on progesterone therapy during my pregnancy.
